A liquid processing apparatus has been known that performs a cleaning process of a substrate (hereinafter “wafer”), such as a semiconductor wafer and the like by supplying the substrate with a processing liquid, while rotating the substrate that is held substantially horizontally. For example, Japanese Patent Application Laid-open Publication No. heisei 09-290197 (hereinafter “Patent Document 1”) discloses a liquid processing apparatus including a bottom plate for holding a wafer, a rotation shaft fixed and connected to the bottom plate and driven rotationally by a spin motor, a processing liquid supply tube extended within the rotation shaft for providing a processing liquid to a back surface of the wafer held by the bottom plate, and a substrate-push-up pin capable of supporting the wafer from a lower side by elevating the wafer. With such liquid processing apparatus, a penetrating hole for the processing liquid supply tube through which the processing liquid supply tube is passed, and a penetrating hole for the substrate-push-up pin through which the substrate-push-up pin is passed are provided at the bottom plate, respectively.
However, in the conventional liquid processing apparatus such as disclosed in the Patent Document 1, there is a possibility that the processing liquid, such as a chemical liquid or a rinsing liquid used for cleaning the wafer, may be attached to the substrate-push-up pin through the penetrating hole of the substrate-push-up pin provided at the bottom plate, which is being retreated downward from the bottom plate. Due to this, there has been a case that when the wafer is transferred to a carrying robot by elevating the wafer with the substrate-push-up pin after a drying process of the wafer, the droplet of the processing liquid attached to the substrate-push-up pin may be attached to the back surface of the wafer.
If the processing liquid is thus attached to the wafer, not only a watermark is formed at the wafer itself to which the droplet is attached, but also the humidity in a carrier into which the wafer is carried is increased, adversely affecting other wafers accommodated in the carrier as well.